Tubular conductor



U. MEYER ETAL 2,223,116

TUBULAR CONDUCTOR.

Filed Dec. 28, 1937 Patented Nov. 26, 1940 TUBULAB CONDUCTOR ABraumandFransUnterl Mulheim. Colognaandclemenskern, Germany, limon toand August Llndlau. Cologne-Mannini,

Felten Guilleaume carlswerk Act-ien Gesellschaft, Cologne-Mul.

heimGermany Application December z8, 1931, Serial No. 182,128 In GermanyJanuary 23, 1937 2 claims, (ci. 174-130) The present invention relatesto tubular conductors and particularly pertains to improvements incables of the air space insulation type.

In a co-pending application maturing as Patent No. 2,165,737 it has beenproposed to manufacture tubular conductors from a plurality of metalbands, more particularly as an outer conductor for high frequencycables, by providing the metal bands along their longitudinal edges withindentations at definite distances from one another. The indentations ofadjacent bands were preferably staggered relatively to one another.Bands provided with such indentations are prevented frombeingindividually laterally displaced. The object of the present inventionisto provide an improvement of such tubular conductors.

In the case of concentric conductors for high frequency currents it isimportant that the diameter of the outer conductor, measuredv at greatdistances apart, shall be as uniform as possible, otherwise theimpedance will be subjecty to fluctuations. It has been found that bandswhich are provided at short distances apart, with indentations intheform of transverse grooves, mutually support one another very well,since the transverse grooves prevent the bands from sliding over oneanother. According to the invention this is ensured to a large extent bythe metal bands being provided with indentations in the form oftransverse grooves and by being preshaped in such a way that, after theyhave been stranded together, a circular cross-section is obtained.Around the tubular conductor there vis preferably wound a further bandwith a comparatively short laying length in order to keep together thebands of the outer conductor. An outer conductor, constructed in themanner referred to, is pressure resisting and also very nexible, evenwhen thethiclmess of the outer conductor is small.

In order further to increase the stability the transverse grooves may,according to the invention, be provided with projecting parts. Theprojections engage with the bands which abut against one another andprevent a lateral displacement between the bands, while a relativelongitudinal displacement is possible in the interval between theconsecutive projections. An unlimited possibility of displacement in thelongitudinal direction may be obtained by providthe two bands abuttingagainst ting out portions of the transverse grooves of the other band atthe abutting edge. so that the projections of the one band can slidepast at these points.

Other and further features and objects of the invention will be apparentfrom a consideration of the accompanying drawing and the following 5description ywherein an exemplary embodiment of the invention isdisclosed.

In the drawing:

Fig. 1 is a plan view of a cable embodying the invention with partsbroken away. i

Fig. 2 is a perspective view of the bands provided with transversegrooves and illustrating the projecting partsr Fig. 3 is an end view ofthe conductor bands shown in Fig. 2.

Referring to Figure 1, I l is the inner conductor of a concentric highfrequency cable surrounded by the supporting helices I2 of polystyroland the polystyrol bonds i3. Thereon there is provided the outerconductor consisting of preshaped bands 6l and 65, which are providedwith transverse grooves 63 at short distances from one another. Thebands 6I and 63 are held together by a further copper band I6.

The bands are more clearly shown in Figs. 2 and 3 wherein the outerconductor 6| is provided with transverse grooves 63 and projecting partsS4. The projections 64 engage with the abutting tubular half 65 andprevent a lateral displacement between the two tube halves, while Y arelative longitudinal displacement is possible within the intervalbetween the consecutive pron jections. An unlimited possibility ofdisplacement in the longitudinal direction may be obtained by providingonly one of the two abutting bands with projecting parts il, and bycutting out portions of the transverse grooves of the other band $5 atthe points 66, so that the projections il of the opposite band 8| canslide past at these points, as will be seen from Fig. 3, in which onlythe transverse grooves of the upper tube half are provided withprojections i4.

What we claimis:

1. A tubular electric high frequency conductor consisting of a pluralityof metal bands stranded together and having indentations in the form oftransverse grooves extending at right angles to the plane of the bands,said bands being Preeral displacement between adjacent bands.

2. A tubular electric high Ifrequency conductor consisting of aplurality of metal bands stranded together and having indentations y inthe formo! transverse grooves extendingiat right angles to the plane ofthe bands, said bands being preshaped in such a manner that thebandshave a circular crs-section when arranged with v the edges thereofadjacent each other, said indentations terminating in projectionsextending 10 beyond at least one edge of some oi the bands and saidindentations having recesses at edges thereof adjacent said projectionsso that the band nally with respect to the band providedwith re- ULFILASMEYER.

AIFRED BRAUN. FRANZ UNTERBUSCH. `AUGUST LINDLAU. CLENIENS KERN.

CBSSES.

`carrying the projections may move longitudi-

